Prior housed power staplers have included those shown in U.S. Pat. No. 4,720,033 in which a drive-control unit powers the stapler blade down to staple and then back up again. Other powered staplers are disclosed in U.S. Pat. No. 4,542,844 and an unjamming arrangement is shown in U.S. Pat. No. 4,913,332.
Housed staplers for selectively stapling multiple sheets heretofore have failed to achieve full success in stapling stacks employed in heavy duty applications.